fix(core): deleting Slicker object caused issue with cache

[ghiscoding]

• previous PR fix(memory): clear & dispose of grid to avoid mem leaks & detached elm #606 to avoid mem leaks actually create an unintended issue, with Salesforce at least, caching broke because Slicker was no longer exist but the cache think it does.

[codecov]

Codecov Report

Merging #635 (3f3e261) into master (bcb11cd) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #635   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          230       230           
  Lines        16396     16395    -1     
  Branches      5459      5459           
=========================================
- Hits         16396     16395    -1     

Impacted Files	Coverage Δ
...bundle/src/components/slick-vanilla-grid-bundle.ts	100.00% <ø> (ø)

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